(The Ontario 2100 Footers List is based on the ‘Ontario’s Highest Elevations’ list compiled by Brian Back of Ottertooth.com with assistance of Paul Harker of the Atlas of Canada at Natural Resources Canada, and Greg Slayden of Peakbagger.com. Elevation measurements were taken from the 1:20,000-scale Ontario Base Maps (OBM) series produced by Ontario’s Ministry of Natural Resources. These maps feature a 10-metre contour interval and an extensive set of spot heights for which the ministry reports a vertical accuracy of 2.5 metres. Contour interval accuracy is 5 metres.)